Field of the Invention
The present invention relates to a lens driving device, and in particular to a lens driving device with a 3-axis closed loop stabilization system.
Description of the Related Art
With the growing popularity of portable devices equipped with a camera, users become used to use the camera function of the portable device. However, the users generally do not prepare a tripod to stabilize the portable device when they use the portable device to shoot a picture. Therefore, under an environment with insufficient light, the photo is often blurred because of camera shake.
The commonly used anti-shake method includes optical image stabilization (OIS), which moves the optical lens module or photosensitive module to offset the influence due to camera shake to maintain a stable optical imaging system. In the past, a 2-axis closed loop stabilization system has been often used, and the shake in the direction parallel to the photosensitive plane can be compensated. If the shake in the direction perpendicular to the photosensitive plane (the optical axis direction) is tried to be compensated, a position sensor for the optical axis direction, for example a hall element, should be disposed.
However, the position sensor for the optical axis direction is installed in an autofocus (AF) module. The position sensor needs to be electrically connected to a circuit board located in the optical image stabilization module. In addition, a driving coil installed in the autofocus module also needs to receive a driving signal transmitted from the circuit board. In a compact lens driving device, the signal transmitting path has to be arranged in a limited space. Therefore, how to save space to simply assemble a 3-axis closed loop stabilization system in a lens driving device is still a problem on the market for many years which needs to be solved.